Police-alarm system



(No Model.)

J. 0. WILSON.

POLICE ALARM SYSTEM. No. 392,248. Pat-entd Nov. 6, 1888. I

XMW WDM. aamawasmw I JOHN G. \VILSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE MU- NICIPAL SIGNAL COMPANY, OF PORTSMOUTH, NEWV HAMPSHIRE.

POLICE-ALARM SYSTEM.

SPECIFICATION forming part of Letters Patent No. 392,248, dated November 6, 1888.

Application filed January 14, 1888. Serial No. 260,692.

To all whom it may concern:

Be it known that I, JOHN 0. WILSON, 0 Boston, county of Suffolk, and State of Massachusetts, have invented an Improvement in Police-Alarm Systems, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention has for its object to construct an electric switch especially adapted for use in a central office or receiving-station of a policealarm system to introduce a telephone in any one of several circuits entering the said office or station, whereby but one telephone need be used at the central ofiice for all the circuits.

The invention consists in the combination, with two or more metallic or signaling circuits having ground branches including telephones, of a common ground branch for all the circuits, which includes a telephone, and a rotary switch operated by the movement of a pointer over a suitable dial or index for connecting said common ground branch with any one of the said signal-circnits, all substantially as will be hereinafter more fully pointed out. In this instance the switch consists of a rotatable cylinder, to which the pointer is attached, said cylinder having several studs or projections arranged spirally upon its surface, the number of studs corresponding with the number ofsignaling-circuits, and several contact-pens, also corresponding in number with the number of signaling-circuits, are arranged to co-operate one with each stud as the cylinder is revolved, said contact-pens constituting the stationary member of the switch. The contact-pens are connected, respectively, with the several signaling-circuits, and the rotatable cylinder is connected with the common ground branch, so that by rotating the cylinder one or another is brought into position to co-operate with its respective contact-pen, to thereby connect the common ground branch with that signaling circuit to which said contact-pen is attached.

Figure 1 shows in top or plan view a rotary switch embodying this invention; and Fig. 2, a diagram showing several signaling-circuits each having several ground branches, including telephones, a rotary switch, and a common ground branch for all the circuits at the central office, including a single telephone.

(No model.)

The signaling-circuits a, four being herein shown, are metallic circuits, to contain in this instance several signal-boxes of any wellknown construction and indicated upon the drawings by circles. Each signaling-circuit a enters the central office or receiving-station and includes any suitable signalreceiving-apparatus. (Not shown.) The signaling circuits a each contain several ground branches, 2), leading from the signal-boxes, which boxes include the usual telephone transmitter and receiver, 25, and preferably a condenser, if, said ground branch being normally held open by the usual gravity-switch.

It is designed to communicate to and from the central oiiice or receiving-station by telephone, and hence, instead of employing a telephone at the central office in connection with each signal-circuit entering therein, one transmitting and receiving telephone only, as p, is employed, which is included in a common ground branch, 0, containing a condenser, c. A rotating switch is employed to connect the said common ground branch with any one of the signal-circuits, said switch herein consisting of several contact-pens, 2 34 5, connected, respectively, with the four signaling-circuits a by wires 6, said pens constituting the stationary member of the switch.

A cylinder, (1, having upon its surface several studs or projections, as 7 8 9 10, arranged spirally, is mounted to revolve in suitable bearings in the frame or case A, and said studs engage one or another of the contact-pens as the cylinder is revolved.

The cylinder is connected with the common ground branch or wire, 0, to thereby connect said common ground branch with any one of the signaling-circuits, depending upon the position of the cylinder. A pointer, 0, is attached to the shaft of the cylinder d, which moves over the dial or index upon the top surface of the case A, the position of the pointer of the said dial or index indicating the particular circuit with which the common ground branch is connected. The index has one point marked zero, for instance, upon which the pointer normally rests, in which position the common ground branch is normally held open.

The index, instead of having marked thereon the number of the circuits, may have marked thereon the numbers of the several signal-boxes included in the several circuits.

\Vhen it is desired to communicate by telephone with any one of the signal-boxes, the person at the signalbox closes the ground branch by removing the telephone from the gravity-switch and the person in charge at the central ollice or station moves the pointer to occupy the position on the dial or-index to correspond with that particular circuit, thereby connecting the common ground branch with that particular circuit, and by removing the tclcphoncp from the gravity-switch the said common ground branch is closed to complete the telephone-circuit.

The device is very simple in construction and renders it unnecessary to employ but one telephone at the main station for any number of signaling-clrcuits, and no skill is required to operate it.

I am aware that it is old to provide signaling-circuits with ground branches including telephones and at a central station to provide a single ground branch including a telephone, and to employ with each signaling'circuit a distinct and indcpendcntly-operable switch to connect said single ground branch with the signalingcircuit, and such I do not herein broadly claim.

1.. In a police signal system, the combination, substantially as described, of two or more signaling-circuits having ground branches i11- cluding telephones, and a common ground branch including a telephone, with a rotary switch for connecting said common ground branch with any desired one of the signalingcircuits, a pointer for moving said switch, as described, and a dial or index with which the pointer co-operatcs.

2. The combination, substantially as described, with two or more sigualingcircuits having ground branches including telephones, and a common ground branch including a telephone, of aswitch torconnecting said common ground branch with any signaling-circuit desired, said switch consisting ofa rotatable cylinder having arranged spirally upon its surface several. studs or projections, a series of contact-pens adapted to engage said studs or projections, a pointer for moving the cylinder, and a dial or index with which the said pointer cooperates.

In testimony whereof Ihavesigned my name to this specification in the presence of two subscribing witnesses.

JOHN C. \VlL-SO'N.

\Vitnesses:

BERNICIG .l'. Novas, F. L. 151mm. 

